Treat warnings as errors for initial projects (#15019)

* Treat warnings as errors for Umbraco.Cms, Umbraco.Cms.Api.Common and Umbraco.Cms.Api.Delivery projects.

* Treat warnings as errors for Umbraco.Cms.Imaging.ImageSharp and Umbraco.Cms.Imaging.ImageSharp2 projects

* Treat warnings as errors for Umbraco.Cms.Persistence.EFCore.Sqlite, Umbraco.Cms.Persistence.EFCore.SqlServer and Umbraco.Cms.StaticAssets

* Treat warnings as errors for Umbraco.Cms.Targets

* Treat warnings as errors for templates/Umbraco.Templates and Umbraco.JsonSchema

* More projects with warnings as errors.

* Reverted warnings as errors due to some file changes since the update.

* Remove unwanted tag

* Removed warnings as errors on TestData project

* Implement warnings as errors in props file, and exclude specific warnings where appropriate as per PR review suggestions.

* Reverted spaces

* Revert "Reverted spaces"

This reverts commit 3734c45e2270c3324768b33e459aefcc6a8c4739.

* Update sdk version to fully support Umbraco.code 2.2.0 dependency on Microsoft.CodeAnalysis.CSharp.Workspaces 4.10.0

* Ignore PathToLongErrors for now in static assets

---------

Co-authored-by: Emma Garland <emma.garland@rocksolidknowledge.com>
Co-authored-by: Sven Geusens <sge@umbraco.dk>

src/Umbraco.Web.Website/Umbraco.Web.Website.csproj

@@ -5,7 +5,10 @@
     <Description>Contains the website assembly needed to run the frontend of Umbraco CMS.</Description>
     <RootNamespace>Umbraco.Cms.Web.Website</RootNamespace>
   </PropertyGroup>
-
+  <PropertyGroup>
+    <!-- TODO: Fix all warnings and remove this override -->
+    <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
+  </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\Umbraco.Web.Common\Umbraco.Web.Common.csproj" />
   </ItemGroup>